Mount St. Helens. Prior to 1980, Mount St. Helens formed a conical, youthful volcano sometimes known as the Fuji-san of America. During the 1980 eruption the upper 400 m of the summit was removed by slope failure, leaving a 2 x 3.5 km horseshoe-shaped crater now partially filled by a lava dome.ount St. Helens. Prior to 1980, Mount St. Helens formed a conical, youthful volcano sometimes known as the Fuji-san of America. During the 1980 eruption the upper 400 m of the summit was removed by slope failure, leaving a 2 x 3.5 km horseshoe-shaped crater now partially filled by a lava dome.
Definition of plantar. : of or relating to the sole of the foot plantar wart.
Medical Definition of Plantar fasciitis. Plantar fasciitis: Inflammation of the plantar fascia, the bowstring-like tissue that stretches from the heel bone to the base of the toes. Plantar fasciitis can be due to calcaneal spurs, which typically cause localized tenderness and pain that is made worse by stepping down on the heel.